/*
 * Copyright 2013-2018 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.alibaba.cloud.nacos.registry;

import java.util.List;
import java.util.Properties;

import cn.hutool.core.util.ObjectUtil;
import cn.hutool.extra.spring.SpringUtil;
import com.alibaba.cloud.nacos.NacosDiscoveryProperties;
import com.alibaba.cloud.nacos.NacosServiceManager;
import com.alibaba.csp.sentinel.util.HostNameUtil;
import com.alibaba.nacos.api.exception.NacosException;
import com.alibaba.nacos.api.naming.NamingService;
import com.alibaba.nacos.api.naming.pojo.Instance;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.springframework.cloud.client.serviceregistry.Registration;
import org.springframework.cloud.client.serviceregistry.ServiceRegistry;
import org.springframework.util.StringUtils;

import static org.springframework.util.ReflectionUtils.rethrowRuntimeException;

/**
 * @author xiaojing
 * @author <a href="mailto:mercyblitz@gmail.com">Mercy</a>
 * @author <a href="mailto:78552423@qq.com">eshun</a>
 */
public class NacosServiceRegistry implements ServiceRegistry<Registration> {

    private static final String STATUS_UP = "UP";

    private static final String STATUS_DOWN = "DOWN";

    private static final Logger log = LoggerFactory.getLogger(NacosServiceRegistry.class);

    private final NacosDiscoveryProperties nacosDiscoveryProperties;

    private final NacosServiceManager nacosServiceManager;

    public NacosServiceRegistry(NacosServiceManager nacosServiceManager,
                                NacosDiscoveryProperties nacosDiscoveryProperties) {
        this.nacosDiscoveryProperties = nacosDiscoveryProperties;
        this.nacosServiceManager = nacosServiceManager;
    }

    @Override
    public void register(Registration registration) {

        if (StringUtils.isEmpty(registration.getServiceId())) {
            log.warn("No service to register for nacos client...");
            return;
        }

        NamingService namingService = namingService();
        String serviceId = registration.getServiceId();
        String group = nacosDiscoveryProperties.getGroup();

        /**
         * 自定义策略
         */
        String registerEnabled = SpringUtil.getProperty("spring.cloud.nacos.discovery.register-enabled");
        String active = SpringUtil.getProperty("spring.profiles.active");
        if (ObjectUtil.isNotEmpty(active) && active.equalsIgnoreCase("dev")
                && ObjectUtil.isNotEmpty(registerEnabled) && registerEnabled.equalsIgnoreCase("true")) {
            group = HostNameUtil.getIp() + "@" + active;
            nacosDiscoveryProperties.setGroup(group);
        }

        Instance instance = getNacosInstanceFromRegistration(registration);

        try {
            namingService.registerInstance(serviceId, group, instance);
            log.info("nacos registry, {} {} {}:{} register finished", group, serviceId,
                    instance.getIp(), instance.getPort());
        }
        catch (Exception e) {
            if (nacosDiscoveryProperties.isFailFast()) {
                log.error("nacos registry, {} register failed...{},", serviceId,
                        registration.toString(), e);
                rethrowRuntimeException(e);
            }
            else {
                log.warn("Failfast is false. {} register failed...{},", serviceId,
                        registration.toString(), e);
            }
        }
    }

    @Override
    public void deregister(Registration registration) {

        log.info("De-registering from Nacos Server now...");

        if (StringUtils.isEmpty(registration.getServiceId())) {
            log.warn("No dom to de-register for nacos client...");
            return;
        }

        NamingService namingService = namingService();
        String serviceId = registration.getServiceId();
        String group = nacosDiscoveryProperties.getGroup();

        try {
            namingService.deregisterInstance(serviceId, group, registration.getHost(),
                    registration.getPort(), nacosDiscoveryProperties.getClusterName());
        }
        catch (Exception e) {
            log.error("ERR_NACOS_DEREGISTER, de-register failed...{},",
                    registration.toString(), e);
        }

        log.info("De-registration finished.");
    }

    @Override
    public void close() {
        try {
            nacosServiceManager.nacosServiceShutDown();
        }
        catch (NacosException e) {
            log.error("Nacos namingService shutDown failed", e);
        }
    }

    @Override
    public void setStatus(Registration registration, String status) {

        if (!STATUS_UP.equalsIgnoreCase(status)
                && !STATUS_DOWN.equalsIgnoreCase(status)) {
            log.warn("can't support status {},please choose UP or DOWN", status);
            return;
        }

        String serviceId = registration.getServiceId();

        Instance instance = getNacosInstanceFromRegistration(registration);

        if (STATUS_DOWN.equalsIgnoreCase(status)) {
            instance.setEnabled(false);
        }
        else {
            instance.setEnabled(true);
        }

        try {
            Properties nacosProperties = nacosDiscoveryProperties.getNacosProperties();
            nacosServiceManager.getNamingMaintainService(nacosProperties).updateInstance(
                    serviceId, nacosDiscoveryProperties.getGroup(), instance);
        }
        catch (Exception e) {
            throw new RuntimeException("update nacos instance status fail", e);
        }

    }

    @Override
    public Object getStatus(Registration registration) {

        String serviceName = registration.getServiceId();
        String group = nacosDiscoveryProperties.getGroup();
        try {
            List<Instance> instances = namingService().getAllInstances(serviceName,
                    group);
            for (Instance instance : instances) {
                if (instance.getIp().equalsIgnoreCase(nacosDiscoveryProperties.getIp())
                        && instance.getPort() == nacosDiscoveryProperties.getPort()) {
                    return instance.isEnabled() ? "UP" : "DOWN";
                }
            }
        }
        catch (Exception e) {
            log.error("get all instance of {} error,", serviceName, e);
        }
        return null;
    }

    private Instance getNacosInstanceFromRegistration(Registration registration) {
        Instance instance = new Instance();
        instance.setIp(registration.getHost());
        instance.setPort(registration.getPort());
        instance.setWeight(nacosDiscoveryProperties.getWeight());
        instance.setClusterName(nacosDiscoveryProperties.getClusterName());
        instance.setEnabled(nacosDiscoveryProperties.isInstanceEnabled());
        instance.setMetadata(registration.getMetadata());
        instance.setEphemeral(nacosDiscoveryProperties.isEphemeral());
        return instance;
    }

    private NamingService namingService() {
        return nacosServiceManager.getNamingService();
    }

}
